1 files changed, 38 insertions, 0 deletions
diff --git a/Source/cmPathLabel.cxx b/Source/cmPathLabel.cxx
new file mode 100644
index 0000000..491d2f0
--- /dev/null
+++ b/Source/cmPathLabel.cxx
@@ -0,0 +1,38 @@
+/*============================================================================
+  CMake - Cross Platform Makefile Generator
+  Copyright 2000-2009 Kitware, Inc., Insight Software Consortium
+
+  Distributed under the OSI-approved BSD License (the "License");
+  see accompanying file Copyright.txt for details.
+
+  This software is distributed WITHOUT ANY WARRANTY; without even the
+  implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+  See the License for more information.
+============================================================================*/
+
+#include "cmPathLabel.h"
+
+cmPathLabel::cmPathLabel(const std::string& label)
+  : Label(label)
+  , Hash(0)
+{
+  // Use a Jenkins one-at-a-time hash with under/over-flow protection
+  for (size_t i = 0; i < this->Label.size(); ++i) {
+    this->Hash += this->Label[i];
+    this->Hash += ((this->Hash & 0x003FFFFF) << 10);
+    this->Hash ^= ((this->Hash & 0xFFFFFFC0) >> 6);
+  }
+  this->Hash += ((this->Hash & 0x1FFFFFFF) << 3);
+  this->Hash ^= ((this->Hash & 0xFFFFF800) >> 11);
+  this->Hash += ((this->Hash & 0x0001FFFF) << 15);
+}
+
+bool cmPathLabel::operator<(const cmPathLabel& l) const
+{
+  return this->Hash < l.Hash;
+}
+
+bool cmPathLabel::operator==(const cmPathLabel& l) const
+{
+  return this->Hash == l.Hash;
+}